The Time Dimension in Research

Another dimension of research is the treatment of time.  Some studies give us a snapshot of a single,
fixed time point and allow us to analyze it in detail.  Other studies provide a moving picture that lets us
follow events, people, or sale of products over a period of time. In this way from the angle of time
research could be divided into two broad types:

a.  Cross-Sectional Research.  In  cross-sectional research, researchers observe at one point in
time. Cross-sectional research is usually the simplest and least costly alternative.  Its
disadvantage is that it cannot capture the change processes. Cross-sectional research can be
exploratory, descriptive, or explanatory, but it is most consistent with a descriptive approach to
research.
b.  Longitudinal Research.  Researchers using longitudinal research examine features of people or
other units at more than one time.  It is usually more complex and costly than cross-sectional
research but it is also more powerful, especially when researchers seek answers to questions
about change.  There are three types of longitudinal research: time series, panel, and cohort.